Method of making piston rings



Apr. 3, 1923.

J. H". BRUNINGA METHOD OF MAKING PISTON RINGS Filed Mar. 15, 1919 Patented Apr. 3, 1923.

oasis JOHN H. BRUHIHGA, 6]? ST. LOU IS, MISSOURI, ASSIGNOR, BY MESHE ASSIGNMENTS,

TO SPYBOSEAL MANUFACTURING COMPANY, OF ST. LOUES, MIS$0UEL A CORPO- RATIQI T OF MISSOURI.

EETHOD or rename rrsron nines.

Application filed EtarchlB, 1919. Serial Ito. 2823949.

To all whom it may concern:

Be it known that 1, JOHN H. BRUNINGA, a citizen of the United States, and residing at St. Louis, Missouri, have invented the new and useful Improvement in Methods of Making Piston Rings, of which the following is a specification.

This invention relates to more particularly, the same.

In the'manufacture of piston rings, and to a method of making iston rings, more particularly of the type in which the ends overlap for the major part of the ring circumference, the rings are cut from a pot or castin of'tubular form and the parting is made i slotting to form a split ring. This, of course, leaves a slot which is liable to cause leakage when the ring is placed on a piston in a cylinder. In some types of rings, this slot is closed by heat treatment of the ring with ends inverted, thereby causing the metal to set so that when the ends are subsequently reinverted, they are pressed together more or less by the resilience that remains so asto more or less close the gap formed.

The process involving heat treatment is not only expensive, and not only results in considerable breakage, but the ring produced is not in ideal form, in View of the the heat treatment of cast iron, of which pis ton rings are usually constructed, is such as to not only impair the resiliency of the ring, but is also liable to cause fracture; moreover, such treatment does not secure complete and permanent closing of the gap.

One of the objects of this invention, there fore, is to provide a method of making piston rings, whereby the ring can be made with minimum amount of labor and mate rial, with practically no breakage, and with maximum efficiency.

Further objects will appear from the detail description taken in connection with the accompanying drawing in which:

Figure 1 is a side elevation of a body blank or pot, showing various operations in order to produce a piston ring in accordance with this invention";

Figures 2 and 3 arerespectively a side ele fact that view, showingthe facing opscribed and illustrated embodiment of this invention, a body blank or pot 1, comprising a casting of cast iron of cylindrical form, is clamped in a chuck 2 or a face plate of a lathe, and the outside thereof is turned to a diameter somewhat greater than the diameter of the finished ring. The inside of the casting can now also be turned to a diameter such as'to produce-a blank of slightly greater thickness than the thickness of the finished ring; as, however, hereinafter described, this machining of the inside of the body blank may be delayed until after other operations are performed, or a may simply be taken.

The pot or body blank is now out helically as shown at 3 from end to end and this cut may becompletely through the body blank in case where the inside of the body blank is turned to proper diameter and ring thickness; or in case the inside finishing is delayed until later, the cutting may be of such a depth as to be slightly greater than the thickness of the completed ring so as to go not quite through, but leave material cdnnecting the helices. This cutting of the helical cut is preferably performed 1n a milling machine, by the use of a thin circular saw.

There will thus be formed on the bodyg blank,

a cut extending helically around its circumference and therealong so as to provide a helically extending band or a series of helical convolutions.

blank is cut intermediate the: own at 4 but-these cuts extend around ths" ircumference; in

The king helices as s only partlyroughing out the particular illustration, shown in Figwhether the inside of the body blank is or is not turned to the required diameter and ring thickness as heretofore described.

The helices so formed on the body blank are separated at the'junctions of the cuts 3 and 4 as by drilling, as shown at 5, at opposite ends of the slots 4 and on axially opposite sides of each slot.- If now the cuts 3 and 4 are formed so as to extend entirely through the body blank, the helices will be separated or if the cuts 3 and 4 extend only h the body blank the heliccs partially throu by turning the inside of the can be separate body blank to ring thickness. One of the, separated helices is'shown in Figures 2 and 3.

Upon reference to Figures 2 and 3, it will be seen that there is thus produced a ring v blank, having its ends 6 and 7 overlapping for a major part of the ring circumference (in the articular illustration for about onehalf'of its circumference) but with the ends inverted with respect to their position in the finished ring. By now inverting the ends of the ring blank, Figures 2 and 3, the blank will be in the form shown in Figure 4, in which one overlapping end will lie within a recess in the other overlapping end, so that the overlapping ends are mutually inter-- positioned.

By referring again to Figures 1 to 4 inelusive, it will be noted that the helical cut 3 forms the side faces of a series of connected inverted ring blanks, whilethe cuts 4 form the parting faces thereof. The cut 3 extends continuously and circumferentially of the body blank, while the cuts 4 extend' only part circumferentially-that is, only partly around the blank in a circumferential direction. The direction of the cuts 4 depends upon the character of the overlapping ends; thus if the overlapping ends are tapering to blunt ends and extend for about one-half of the circumference, these cuts may lie in parallel planes at ri ht angles to the axis of the body blank and isect the helices as shown in igure 1; if, however, the overlapping ends are of uniform width, then these cuts 4 should be in the form of semi-helices intermediate or bisecting the helices formed by the cut 3 and parallel thereto but extending only part circumferentially around the ring blank as shown in application Serial Number 282,295 filed of even date herewith. Furthermore, the extent of the cuts 4 circumferentially around the ring blank will depend upon the extent extend for more or less respectivel the required diameter and:

cumference; if, however, the ends are to 7 overlap for more or less than one-half of the ring circumference, then the out should than one-half of the rin circumference. n this the extent and be varied in accordance with the extent and inclination of the cuts 4; in this way, the ring of any desired form-can be obtaine It will, of course, be understood that it is not necessary to proceed in making the cuts in exactly the order described, since it will be obvious that the cuts 4 may be made before the cuts 3; in fact, where the cuts extend. completely through the body blank, it

is desirable to form-the cuts 4 first in order to maintain the required rigidity of the body blank; for" it will be noted that the cuts 4 form the parting faces and they require, therefore,'the greater accuracy; accordingly, the material in order to prevent springing and, therefore, inaccuracy in the formation of these parting faces.

After the tin blank has been formed as shown in Figures shown in Figure 4, so that the overlapping ends are interpositioned, one within a recess in the other, the ends are gapped as shown at 8, in order to permit contraction of the ring in to give the ring the desired radial tension; it is understood, of course, that the length of the gap is sufficient so that when the ring blank is contracted to a slightly greater diameter than the finished diameter, the gap, 1

will be substantially closed as shown in Figures 6 and 7. The ring will now be dressed laterally and circumferentially in any suitable manner; thus, as illustrated in Figure 6, the ring blank is placed in a re.- 110 rings clamped in position and dressed cir- 1% cumferentially to the required diameter. The finished ring is shown in Figure 8. It will be noted that the rin blank as produced from the body blank an as shown in Figures 2 and 3 is naturally in inverted condi- 125 tion; if, therefore, the ends are inverted as shown in Figure 4. the ring is placed. under lateral tension so that the overlapping ends will be held in sidewise engagement throughout their length by the original inherent 130 character ofthe lap can 75 between the cuts should be rigid 2 and 3, andinverted as the subsequent operations and so as provided with a magnetic thus been iii 'blanks, and inverting the resiliency of the ring. In the finished ring, therefore, the overlapping ends will not only be held in yielding engagement sidewise, but will also be normally expanded so that When the ring is placed on the piston and in the cylinder, for which it Was designed, it will bear With'a yielding tension on the cylinder Walls and with the overlapping ends in firm yielding engagement. It will be noted that the ring has not been subjected to any heat treatment so that its resiliency is not destroyed or impaired. Furthermore, in ac cordance with the method embodying this invention, there is only a single inversion of the ring. It will furthermore be noted that in view of the fact that the ring blanks are formed from a body blank as a series of connected helices, there is no Waste of material so that the greatest number of rings can be formed from a given body blank orpot casting.

It isobvious that various changes may be made in-the details of the method employed, within the scope of the appended claims, Without departin from the spirit of this invention; it is, t erefore, to be understood that this invention is not to be limited to the details described and shown.

laving thus described the inventiomwhat is claimed is:

1. The method of making piston rings, comprising, cutting a body blank to form the side faces of a series of connected invertcd ring blanks, cutting the body blank to provide the parting faces of the ring blanks, separating the, ring blanks, and inverting the ends of the ring blanks.

2. The method of making piston rings, comprising, cutting a body blank circumferentially to form the side faces and the parting aces of a series of connected inverted ring blanks, separating the ring ends of the ring blanks.

3. The method of making piston rings, comprising, cutting a body blank continuously to form the side faces and partially to form the parting faces, of a series of-connected inverted ring blanks, separating the ring blanks, and inverting the ends of the -ring blanks.

4. The method of making piston rings, comprising, cuttings body blank helically to form the side facesand circumferentially to form the parting-faces, of a inverting the endsof the mug blanks.

5. The method of making Piston rings; comprising, cutting a body blank helically,

cuttin the body blank circumferentially i n-fi terme iate the helices,jseparat1 the helices,

comprising, cutting a body to separate the diate the helices,

comprising, forming a body series of camnected 1nverted ring blanks, separating the j-Jl. Th ring blanks, and

body blank helically,

cutting the body blank circumferentially intermediate the helices, separating the helices at junctions of the cuts, and inverting the ends of the helices.

7. The method of making piston rings, comprising, cutting a body blank helically, cutting the body blank part-circumferen-- tially intermediate the helices, separating the helices at the ends of the circumferential cuts, and inverting the endsof the helices.

8. The method of making piston rings, comprising, cutting a body blank helically, cutting the body blank part-circumferentially intermediate the helices, cutting the body blank at the ends of the circumferential cuts to separate the helices, and inverting the ends of the helices. i

9. The method of making piston rings,

comprising, cutting a body blank helically, cutting the body blank part-circmnfe'rentially intermediate the helices, cutting the body blank oppositely at the ends of the circumferential cuts to separate the helices, and inverting the ends of the helices.

10. The method of making piston. rings, comprising, cutting a body blank helically, cutting the body blank nart-circiunferentially intermediate the helices, cutting the bcdy'blank axially from the ends of the circumferential cuts to the helical cuts to separate the helices, and inverting the ends of the helices.

11. The method of making iston rings, blank helically, part-circumferencutting the body blank tially intermediate the helices, cutting the body blank oppositely at the ends of the oilcumferential and axially to the helical cuts helices, and inverting the ends of the helices. r

12. The method of making piston rings, comprising, forming a body blank to vide a helically extending band, cutting the body blank part circumferentiallv intermesevering the helices at the ends of the circumferential cuts, and inverting the ends of the helices.

13. The method of making piston rin s,

vide a series the body bl mediate the helices, severing the helices at the ends of the circumferential'cuts, and-inverting the ends of the helices. I

e method of making piston rings, comprising, cuttinga body blank o provide a series of connected ring blanks with overlapping ends having outside faces correof helical convolntions, cutting spondingto the ring parting, separating the ring blanks, and ring blanks. Y

inverting the endsof the blank to pro-v ank part-ciroumferentially inter-- 15, The methodjof making piston rings,

comprising, cutting a body blank to form a series of connected .nng blanks', cutting the fi 16. The method of making piston rinfs, comprising, cutting a body blank helically meonoo body blank to form the outside faces of overintei'mediate the helices to correspond with lapping ends of the-ring blanks, separating. the ring lap, separating the ring blanks, the ring blanks, and inverting the ends of and inverting the ends of the ring blanks. the ring blanks. In testimony whereof I afiix my signature this 11th day of March, 1919.

and cutting the body blank circumferentia y Y JOHN H. BRUNINGA. 

